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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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25th Nov 2020, 6:58 pm | #1 |
Pentode
Join Date: Jul 2020
Location: Falkirk, Stirlingshire, UK.
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Bush AC34 restoration - quiet audio, help, please.
Bush AC34 restoration - quiet audio, help, please.
Guy's Have attempted a restore of what is quite a large set, to me anyway. I acquired this for £20, which seemed like a good deal when you look at all the workmanship on this. The case was in poor condition, the laminate peeling, scratched and missing in sections. Spent a few days on the case and replacing all the wax caps, before attempting to power up. Audio is there, but very quiet, a couple of stations on MW, no external aerial plugged in for the test, hum from the speaker, but all quiet when the external speaker knob un-screwed on the rear, so somethings working. Any pointers on where to start appreciated, no voltages checked so far. Thanks again |
25th Nov 2020, 7:04 pm | #2 |
Pentode
Join Date: Jul 2020
Location: Falkirk, Stirlingshire, UK.
Posts: 200
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Re: Bush AC34 restoration - quiet audio, help, please.
Sorry, forgot to mention, resistors all check out OK.
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25th Nov 2020, 9:05 pm | #3 |
Nonode
Join Date: Nov 2016
Location: Aberaeron, Ceredigion, Wales, UK.
Posts: 2,883
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Re: Bush AC34 restoration - quiet audio, help, please.
Just as a starter switch to Gram and touch the PU sockets with metal probe , or your finger, with volume control turns right up you should get a Healthy buzz.
John |
25th Nov 2020, 9:12 pm | #4 |
Nonode
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Location: Aberaeron, Ceredigion, Wales, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
Sorry I should have asked do you have the service manual or circuit diagram?
John |
25th Nov 2020, 9:12 pm | #5 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
Hi Scot, voltage checks I'm afraid it has to be.
If you have the service data from the forum note that if your figures are within 10% of the values given there is no problem. Also observe if anything is getting hot and resist the temptation to twiddle the coil cores and trimmer caps Ed |
25th Nov 2020, 9:48 pm | #6 |
Pentode
Join Date: Jul 2020
Location: Falkirk, Stirlingshire, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
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25th Nov 2020, 9:50 pm | #7 | |
Pentode
Join Date: Jul 2020
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Re: Bush AC34 restoration - quiet audio, help, please.
Quote:
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25th Nov 2020, 10:25 pm | #8 |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
You WILL need an aerial to hear anything meaningful. It will be very quiet without one.
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25th Nov 2020, 11:43 pm | #9 |
Dekatron
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Re: Bush AC34 restoration - quiet audio, help, please.
Most of my radios here would be pretty dead without an external aerial...at least ones without their own internal aerial like yours.
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Kevin |
26th Nov 2020, 2:10 am | #10 |
Heptode
Join Date: Jul 2008
Location: Hereford, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
Looking at the second pic it looks like some of the pF caps in the RF stages have been replaced... Built in frame aerial for MW/LW.
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26th Nov 2020, 9:40 am | #11 |
Rest in Peace
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Location: Basildon, Essex, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
What are those blue caps on the tag strip.
Mike |
26th Nov 2020, 9:54 am | #12 |
Dekatron
Join Date: Feb 2009
Location: Chesterfield, Derbyshire, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
Looks like the mica capacitors have been replaced! That needs checking out.
Mick. |
26th Nov 2020, 4:28 pm | #13 |
Pentode
Join Date: Jul 2020
Location: Falkirk, Stirlingshire, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
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26th Nov 2020, 4:29 pm | #14 |
Pentode
Join Date: Jul 2020
Location: Falkirk, Stirlingshire, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
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26th Nov 2020, 5:31 pm | #15 |
Dekatron
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Re: Bush AC34 restoration - quiet audio, help, please.
Yes!
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26th Nov 2020, 6:02 pm | #16 |
Nonode
Join Date: Nov 2016
Location: Aberaeron, Ceredigion, Wales, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
Do I understand correctly that the Radio works, after you changed the components, as you say in post #1, but with low volume?
John |
26th Nov 2020, 9:55 pm | #17 | |
Pentode
Join Date: Jul 2020
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Re: Bush AC34 restoration - quiet audio, help, please.
Quote:
Cheers Lee |
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26th Nov 2020, 10:16 pm | #18 |
Heptode
Join Date: Jan 2006
Location: Cornwall, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
The reason the advice is given not to change the pF values is that they are rarely faulty and to change them may affect the alignment. However, now that you have changed them, there is no point putting old wax types back in.
The best thing is to follow the advice in post 5 and carry out voltage checks. Changing the capacitors may not have affected alignment too badly and it's best not adjusted without a signal generator. |
27th Nov 2020, 11:42 am | #19 |
Pentode
Join Date: Jul 2020
Location: Falkirk, Stirlingshire, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
Cheers Simon
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27th Nov 2020, 2:09 pm | #20 |
Octode
Join Date: Jan 2009
Location: Falmouth, Cornwall, UK.
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Re: Bush AC34 restoration - quiet audio, help, please.
Did you change any pF caps inside the cans ?
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